Malicious PDF — malware analysis report

Static analysis result for SHA-256 779f9f3dbc43a15f…

MALICIOUS

PDF

61.0 KB Created: 2021-09-05 01:25:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2031690f97c5471fef4bc94d743ba449 SHA-1: 2168fe532bb232af58ddfcdf6fe3054d2254c520 SHA-256: 779f9f3dbc43a15f6fd48e5c1e7f5c782d3656558c0d9d0a7c13f2474252d3f3
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is designed as a screenshot lure, containing a single image and a clickable link to a compromised WordPress site. This site hosts another PDF, which is likely the actual malicious payload. The ClamAV detection and ML classifier strongly indicate malicious intent, consistent with phishing and trojan delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5428

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 60 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://dermatologomiguelgallego.com/miguel/fck/file/92351539506.pdf In PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/fe3e6fed5d5c2d204d31e48f6c207e57/rumezekeso.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56a22e5b4f---63450203318.pdfIn PDF document text
    • http://dxqzx.com/ckfinder/userfiles/files/20210820_181124.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/vbavj205cdulh4cimrblv72cug/nanejunofovizokenidudor.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/26402615083.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/84641784082.pdfIn PDF document text
    • http://www.asslar.de/downloads/tadum.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6afac8e27f---5473708651.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/10710492249.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d1ee854885---bulotirajojirefewo.pdfIn PDF document text
    • https://justbuymeds.net/userfiles/file/85476887219.pdfIn PDF document text
    • http://axwelindia.com/uploads/25546866493.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887e4659b04---58184184242.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/53663095559.pdfIn PDF document text
    • http://mudrberanova.cz/userfiles/file/42228844409.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/6444286286.pdfIn PDF document text
    • https://vpmemorial.net/images/file/59416086446.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/32225346586.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/v61m4ifee8sn2otb63rcas27uq/55672903074.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210819/files/20210819061814.pdfIn PDF document text
    • http://hnysft.com/d/files/45248110425.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/46377614233.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/ec4676308d29f9ee6d44dc134e7e1532/12793832677.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=computer+security+pdf+notesPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b483.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB483 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9A 10816 bytes
SHA-256: 33cbc53546f4c1b46caf60504adcc9000042eb60efb2e07c8a4a590615142a41